


Sex Ed

by sup_ma_boi



Category: Shingeki no Kyojin | Attack on Titan
Genre: Anal Fingering, Bottom Eren, Bottom Eren Yeager, First Kiss, First Time, Gay Sex, Loss of Virginity, M/M, Orgasm, Smut, Top Reiner, Virgin Eren Yeager, bottom!Eren
Language: English
Status: Completed
Published: 2020-05-07
Updated: 2020-05-07
Packaged: 2021-03-02 22:29:08
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,106
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24064348
Author URL: https://archiveofourown.org/users/sup_ma_boi/pseuds/sup_ma_boi
Summary: Eren wanted to know what sex was. His parents were dead, and his friends didn’t want to tell him.But he knew exactly how to learn.
Relationships: Reiner Braun/Eren Yeager
Comments: 5
Kudos: 399





	Sex Ed

The subject of sex had always eluded Eren. He'd always heard of sex and its wonders, but he never got the opportunity to have "the talk" with his parents before they died. And he couldn't ask his friends because they wouldn't give him an explanation.

"You'll learn when it's your time," Mikasa always told him. And when he asked when his time would be, she simply shrugged and went back to whatever she was doing. Armin had virtually no interest in sex and therefore had no information on the matter besides what he'd read in books.

He'd tried asking Jean, but all he got in response was a tease.

"Poor Yeager," Jean jeered. "He's never gotten his dick wet."

"What does that even mean?!" Eren asked in frustration.

Jean just scoffed and walked off, talking to Reiner or-

Wait.

Reiner!

Eren had hardly ever spoken to Reiner other than a friendly hello, but he knew that Reiner was older and had a lot of experience.

So the next time Eren saw Reiner in the mess hall, he talked to him.

"Can I talk to you privately?" the emerald-eyed boy asked confidently.

Reiner's conversation halted abruptly, the taller boy looking down at Eren.

"Uh, sure?"

Eren led Reiner outside, looking around to make sure that nobody was within earshot. The shorter male took a deep breath and looked up at Reiner.

"Can you teach me about sex?"

Reiner choked on his breath.

The air was dead silent as the two boys stared at each other: Eren staring in anticipation and Reiner staring in disbelief.

"Please tell me you're joking."

A small blush fell onto Eren's cheeks.

"I am nowhere near joking. Nobody else will teach me and you're one of my last options."

"No way, kid."

Reiner had heard and seen a lot about Eren. The kid was hot, sure, but his spicy attitude and Reiner's lack of patience would probably lead to a fire if they talked about sex. Reiner would probably end up fucking the brains out of the poor kid.

As Reiner tried to walk off, Eren ran in front of him, blocking his path.

"You have to teach me! I'm the only cadet who hasn't a clue about what sex is or what it's like! Please!"

"No way kid."

"What? Are you scared? Stop being such a pussy and tell me about sex!"

Reiner's answer faltered. That was exactly the feisty shit that Eren was prone to. And when Reiner thought about it, he realized Eren did have a sexy little body: tight abs and cute little nipples and a juicy ass with thighs and hips to match. Reiner had touched himself to the thought of Eren's lithe body before.

"Fine," Reiner breathed. "Come with me to my room. But statements like that will get you more than you're bargaining for."

Eren internally celebrated. He would finally get to learn about sex!

The two walked to Reiner's room, and when they entered, the taller male locked the door behind them.

"So what do you want to know?"

"Everything."

Reiner thought for a moment before he began to speak. "So basically sex is when two or more people touch genitals. Usually, it's only between two people: two females, two males, or a male and a female."

Eren listened intently.

"Lucky for you, I specialize in all types."

"I want to know about sex with two guys."

Reiner raised his brow. Sure, Reiner was bisexual, but he never would've thought that Eren would like dick.

He actually could get to fuck the kid.

"So when two guys fuck," Reiner began, "One is the top and one is the bottom. The top is the one who puts the dick in the bottom's ass."

"Are you a top or a bottom?"

"I'm a top."

"So what am I?"

"You won't know until you try both and figure out which one you like more."

Eren frowned. "Okay so what do I do about my feelings?"

"Feelings?"

"It's like, sometimes I have these weird feelings and my dick gets stiff and I can't make it go away."

Reiner almost wanted to laugh at how inexperienced the kid was.

"You masturbate."

"Master who?"

Reiner rolled his eyes, and then he had a great idea.

"Rather than explaining, how about I show you?"

Eren blushed deeply. "H-how?"

Reiner placed his strong hands onto Eren's hips, hoisting the boy up and sitting him into his lap. Eren's blush only became deeper.

"What are you-"

Eren's words were cut off with a gasp as the taller boy pressed their lips together. Reiner took the gasp as an opportunity to slide his tongue into the brunet's mouth, licking around the inside of the warm cavern. The smaller boy sighed softly, closing his mouth and making his best attempt at kissing back.

Reiner placed his hands onto Eren's hips, pulling the boy down as he ground their crotches together roughly. Eren let out a loud moan at the friction, pulling away from the kiss.

"I won't show you what masturbation is. Not this time. For this lesson, we'll jump straight to the conclusion: sex."

Eren gulped nervously. He would never admit to fear of any sort, but Reiner was a big guy, and Eren was sure that Reiner was going to be big everywhere. How was his dick going to fit inside Eren?

Reiner laid Eren down onto the bed, crawling on top of the smaller boy and immediately beginning to nip and lick at the boy's neck roughly, drawing small yelps out of Eren.

"This is called foreplay, Eren. We tease each other until we can't take anymore."

"What if I already can't take anymore?"

Reiner chuckled lowly.

"Fine. I'll indulge you this one time, but next time, you'll be begging for me."

Eren blushed. He was already on the verge of begging, so he couldn't imagine how he would feel if Reiner were to tease him

The brunet was snatched from his thoughts when Reiner pulled his pants off, revealing Eren's entire lower body. Eren fumbled to cover himself; his face turned a deep shade of red.

"Reiner!"

"What? I'm just trying to check out the merchandise."

"You could've warned me first!"

"There's no fun in warnings. Plus, you're cute when you're flustered."

The blond's words only spread Eren's blush, the crimson spreading down his neck.

"And you blush so pretty, too."

Eren moved his hands from his crotch and covered his face.

"Don't try to act all embarrassed now. You're literally about to get fucked."

Reiner moved over to the small nightstand next to his bed, opening the drawer to dig for his lube.

"This is lube. It's used mostly with guys because girls produce their own lubricant."

"Why can’t I produce my own?"

"Because you're not a girl, Eren."

"Oh yeah..."

Reiner chuckled deeply, opening the bottle and pouring some of the clear fluid onto his fingers.

"This is going to feel a bit cold."

Eren gasped as the blond forcefully spread Eren's legs, placing a finger against the boy's rim. Slowly, Reiner pushed one of his lubed fingers into the hole. Eren squirmed beneath him, squeezing his eyes closed.

"You have to relax or this isn't going to work."

"I'm trying, bastard."

"Watch your mouth," Reiner teased. "Bad boys get punished."

Eren didn't want to be punished, so he took deep breaths and relaxed his body, giving Reiner space to thrust the finger in and out.

"Why are you doing this?"

"Do you want to be split in half? And I don't exactly want you going titan on me."

"But it feels weird!"

Reiner added another finger, thrusting them a bit quicker than he'd previously been thrusting. With each thrust, Reiner angled his fingers differently.

"Holy shit!" Eren gasped, feeling the fingers brush against something inside of him. The brunet let out a loud moan as the blond began to assault the spot, grinding his fingers against it. Eren's moans increased in volume when Reiner added a third finger. The boy's thighs began to tremble as Reiner sped up, not giving the boy any leniency as his prostate was abused.

"I- fuck Reiner please!"

"Please what, baby?"

Reiner let his eyes wander along the boy's body. Eren still had that deep, spread blush going on, making Reiner wonder if the red spread down to his chest. Eren probably had the cutest little nipples.. Reiner admired Eren's thighs, the way the muscles tensed and shook as the assault continued. Eren had such nice, long, tanned legs that were spread open for Reiner like a feast. Eren even had pretty feet.

Reiner's dick was in love with Eren's body.

It was Reiner who was snatched from his thoughts next as Eren released ribbons of hot cum between them. Reiner hadn't even touched the boy's dick, yet he had the poor brunet shaking and gasping for mercy as he orgasmed.

"Reiner... please... no more!" Eren pleaded, squirming to get away from the thick fingers.

Reiner decided to let up, sliding his fingers out of the boy's hole. He watched as the boy clenched around nothing, his hole begging to be filled.

"You ready for me to put it in?"

"That wasn't sex? I thought we were finished!"

Reiner smirked and unbuttoned his pants, allowing this thick, heavy cock to spring free. Eren's emerald eyes went wide.

"Holy fuck, you're huge!"

"I know kid. But I'll be careful with you since it's your first time. Roll over onto your stomach and get on all fours."

Eren prayed to Maria, Rose, and Sina that his poor body wouldn't be pounded to shreds. The brunet did as he was told, arching his back and letting his ass sway in the air.

Without warning, Reiner grabbed Eren's hips and began to push in. Eren let out a broken moan as he was breached, the sound turning into a groan as Reiner bottomed out. Eren felt as if he was about to tear at any moment. He felt so full and raw and lewd. If he knew sex was going to make him feel like such a slut, he would've avoided it at all costs.

At the very least, he would've avoided it with Reiner.

"You alright?"

"Oh yeah I'm fine. It's not like I was just filled by a huge cock without being warned first! I'm definitely great!"

Reiner pulled his dick out until only the tip remained, and then he slammed back into the boy. Eren let out a scream as pain and pleasure overtook him. His arms gave out, and he collapsed onto the bed.

"I was trying to hold back on your little ass. But you insist on being so feisty. Let me show you how bad boys get treated."

Reiner began to fuck Eren in earnest, gripping the supple hips and pulling almost all the way out before slamming back in, over and over again. Soon, Eren's screams of pain and pleasure turned into lewd moans of just pleasure, the older boy's cock somehow honing into Eren's prostate.

"Oh God! Reiner! F-fuck! Harder!" Eren had been trying to hold his tongue, but he was getting railed so good.

Soon, Reiner was pounding into Eren. His balls slapped against Eren's taint repeatedly, making a wet slapping sound that filled the room along with Eren's moans. Eren had never been filled with such ecstasy. Without thinking, he reached a slender hand down to touch himself, but it was slapped away.

"I want you to cum on my cock. No touching."

Reiner released his hold on Eren's hips, instead opting to grab the boy's arms and pin them behind him. Eren only moaned louder at the rough treatment, his arms being pinned bringing a wave of pain that melded with the pleasure.

"R-Reiner! I.... I'm... fuck!"

Reiner forced Eren to arch his back further, allowing the blond to pound harder and deeper, the tip of his cock still hitting Eren's prostate head on.

Eren's second orgasm hit him like a brick. He wanted to writhe, wanted to shake and squirm, but being pinned under Reiner forced him to stay still as he was pounded through his orgasm.

"Oh God! Reiner!"

The lewdness dripping from Eren's overstimulated, fucked-out voice pushed Reiner over the edge. He pulled out hurriedly, releasing his cum all over the boy's tanned back.

Eren gasped for air as he came down from his high. Reiner let go of Eren's arms, allowing the boy to lay down and relax.

"How was that for your first time?"

"It was... amazing."

"So do you think you're a top or a bottom?" Reiner asked.

"Definitely a bottom."


End file.
